This genus of rather typically patterned saturniines is defined by a
number of peculiar features of the male genitalia. The valves are deeply
bifid, the dorsal lobe bearing several long, robust setae dorsally; the
lower lobe is slender, more finely setose. Interior to the valve is a
somewhat conical lobe referred to by Arora & Gupta (1979) as the
labide. The anellus is strongly sclerotised and has a dorsal projection.
There is a massive, rather elongate sclerotised process arising from
between the bases of the valve costas that is considered to be the uncus
by Arora & Gupta and by Michener (1952); the latter suggested the
dorsal process of the anellus was the gnathus, fused to it. The tegumen is
produced dorsally into a narrow, rather weakly sclerotised process. The
saccus is well developed.
The species rosieri Toxopeus shares all these features and therefore
should not be separated in the genus Loepantheraea Toxopeus.

The larvae of both Indian (mylitta Drury) and American (godmani Druce)
species are illustrated by Gardiner (1982), and those of several more are
described. The American species is shown as bright green, smooth-skinned,
with conical spined scoli that are particularly prominent on the thorax
and in the caudal zone. The Indian species is more elongate, tapering
slightly at each end, and has no obvious scoli but is invested with a more
general pilosity, some of which is on tubercles.
The silken cocoon is wrapped in leaf fragments and suspended by a short
stalk from a twig.
The genus is mainly Oriental but there are three species in the New World
and one representative in the S. Moluccas. The status of Australian taxa
attributed to Antheraea needs investigation.